ABSTRACT: This dataset contains LC-MS/MS data in positive ionisation mode of 100 spot urine samples and a pooled sample thereof that were obtained in Glasgow, UK (Institute of Cardiovascular and Medical Sciences & Glasgow Polyomics, University of Glasgow) as part the 'Next Generation Sequencing and Metabolomic Approaches in Stratification of Resistant Hypertension' study for which ethical approval was granted (NHS Ethics Approval Number -14/LO/188). Urine samples have been collected under a range of controlled settings. Informed consent was obtained from all individual study participants. Spot urine samples were taken around 11 a.m. upon a visit to the clinic, 20 1.5 ml aliquots were taken and subsequently centrifuged at 1000 g for 10 minutes after which the supernatant was stored at -80 Celcius until further analysis. A general metabolome extraction procedure was performed as done at Glasgow Polyomics, University of Glasgow, Glasgow, UK (based on Creek et al 2011): i) 5 microL urine was extracted in 200 microL chloroform/methanol/water (1:3:1) at 4 C Celcius; ii) then vortexed for 5 minutes at 4 Celcius; iii) then centrifuged for 3 minutes (13,000 g) at 4 Celcius. The resulting supernatant was stored at -80 Celcius until analysis. A pooled aliquot of all 100 urine samples was prepared prior to the LC-MS/MS runs.
Full details also on LC-MS/MS metabolomics data acquisition and analysis can be found in Van der Hooft et al. 2016, Metabolomics. Chromatography and Mass Spectrometry details: The samples were analysed using a Thermo Scientific Ultimate 3000 RSLCnano system (Thermo Scientific, CA, USA). The pHILIC separation was performed with a SeQuant ZIC-pHILIC column (150 x 4.6 mm, 5 micrometer) equipped with the corresponding pre-column (Merck KGaA, Darmstadt, Germany) - the column temperature was maintained at 25 C. A linear biphasic LC gradient was conducted from 80% B to 20% B over 15 min, followed by a 2 min wash with 5% B, and 8 min re-equilibration with 80% B, where solvent B is acetonitrile and solvent A is 20 mM ammonium carbonate in water. The flow rate was 300 microL/min, column temperature was held at 25 C, injection volume was 10 microL, and samples were maintained at 4 C in the autosampler. MS equipment and settings used: The LC system was coupled to a Thermo Scientific Q-Exactive Orbitrap mass spectrometer equipped with a HESI II interface (Thermo Scientific, Hemel Hempstead, UK). The set up was calibrated (Thermo calmix) in both ionization modes and tuned for the lower m/z range before analysis. Full scan (MS1) data was acquired in positive and negative switching mode in profile mode at 35,000 resolution (at m/z 200) using 1 microscan, an AGC target of 106 cts, a maximum injection time of 250 ms, with spray voltages +3.8 and -3.0 kV, capillary temperature 320 C, heater temperature of 150 Celsius, sheath gas flow rate 40 a.u., auxiliary gas flow rate 5 a.u., sweep gas flow rate 5 a.u, a full scan mass window of 70-1050 m/z, and using m/z 74.0964 (+) and m/z 112.98563 (-) as locking masses. Fragmentation data (LC-MS/MS) was obtained in positive ionization mode as described in (van der Hooft et al 2016). Briefly, a duty cycle consisted of one full scan (MS1) event and one Top5 (or Top10) MS/MS (MS2) fragmentation event, with full scan (MS1) resolution (at m/z 200) was set to 70,000, the AGC target set to 1 x 106, and the maximum injection time set to 120 ms. MS/MS (MS2) resolution (at m/z 200) was set to 17,500, the AGC target set to 2 x 105, MS/MS maximum injection time was set to 80 ms and the underfill ratio was set to 10 %, with a resulting intensity threshold of 2.5 x 105 cts.
Michael Barret 
